Since both remotes have horrible range I think we have indeed identified the culprit as the tint or the antenna amplifier.

It's not a dealbreaker ...... I may not even pursue it any further, after all the remotes do still work - I just found it odd that the range was that much worse than my previous 2 cars, both E46's - one of those with tinted windows as well.

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The word "there" can appear as a pronoun, as in “over there".

"Their" is a possessive pronoun. In a phrase like “Susan and Bill's car,” it could be used to to make a new phrase: “their car.”

”They're” is a contraction of “they are.”
“They are” should always be able to replace “they're.”

Extra credit: It's "I'm looking for an M3" not "I'm looking for a M3".